Upon drilling for and production, transportation, storage, and treatment of crude oil, and upon storage of residual fuel oil obtained during crude oil production, highly toxic sulfides, including hydrogen sulfide and mercaptan, are often generated. Upon drilling for crude oil, a water flooding method may be employed, wherein water is injected into an oil layer such that artificial oil-discharging energy is imparted to the reservoir. Thus, the production rate is maintained, leading to an improved recovery factor. In accordance with the water flooding method wherein water is used, oil remaining in pores in an oil layer is squeezed out after a large amount of oil has been produced by primary recovery, and reservoir pressure is prevented from decreasing upon crude oil production so that it may be maintained. Hydrogen sulfide exists in such water, ground water pumped out with crude oil, crude oil per se, gas contained in such ground water, crude oil, and the like. Further, a light hydrocarbon vapor containing hydrogen sulfide may be emitted from oil well heads. Emission of uncontrolled hydrogen sulfide causes serious health problems. Therefore, it is necessary to control such vapor.
The following methods are known: methods of removing hydrogen sulfide, wherein a hindered amine such as an alkanolamine is allowed to absorb hydrogen sulfide (JP Patent Publication (Kokai) No. 62-129125 A (1987); JP Patent Publication (Kokai) No. 7-258663 A (1995); JP Patent Publication (Kokai) No. 7-258664 A (1995)); and a method for removing sulfides, wherein halonitroalkanol is used (JP Patent Publication (Kokai) No. 2-135138 A (1990)). Further, various methods utilizing adsorption effects have been suggested. Known examples of such methods are a method using activated carbon comprising microcrystalline carbon and poorly graphitized carbon (JP Patent Publication (Kokai) No. 7-214051 A (1995)) and a method using porous carriers upon which copper components are supported (JP Patent Publication (Kokai) No. 2001-123188 A). However, some alkanolamine compounds are combustible and generate an explosive gaseous mixture. Thus, it is dangerous to handle such compounds, and utilization of these compounds requires specialized equipment. In accordance with the methods described above, hydrogen sulfide is selectively removed from a gas containing hydrogen sulfide and carbon dioxide. In addition, 2,2-dibromo-2-nitroethanol (hereafter referred to as DBNE), which is a halonitroalkanol, has an effect of removing sulfides, including hydrogen sulfide and mercaptan; however, it generates unpleasant hydrogen bromide odor, which is a drawback. In addition, DBNE is highly toxic and causes very severe skin irritancy, resulting in serious problems for humans and the environment when handled. Further, 2-bromo-2-nitro-1,3-propanediol (hereafter referred to as BNP) is available at a low cost; however, it must be used in large amounts in order to exert a sufficient effect of removing sulfides. Meanwhile, an adsorption method using activated carbon or the like is readily carried out using simple equipment. However, since the method utilizes physical adsorption effects, the reaction proceeds slowly and treatment is expensive. Further, when the capacity of activated carbon deteriorates, regeneration or disposal of activated carbon is required.